Audi's A6 and S6 have been refreshed for 2015 with a range of subtle improvement aimed at making the large sedan even more appealing.

Pros and Cons

Pros

Biturbo diesel engine is fantastic

Fuel efficiency is strong across the range

Refinement inside the cabin is impressive

S6 is the driver's car

Cons

Aside from the S6, the range is more long-legged tourer than proper sports sedan

Higher model grades are expensive

1.8 TFSI does have some lag at certain speeds

The 2015 Audi S6 4.0 TFSI quattro S tronic might seem the most self indulgent choice, but this model, more than any other in the 2015 Audi A6 range, exemplifies the spirit of a sporting four-door sedan ... certainly the way Audi goes about the genre, anyway.

It’s not cheap, at just under 170 grand, but the combination of comfort, space and a stonking V8 engine is hard to ignore.

We’ve got limited time at launch to get behind the wheel of the models we want to experience, and not every variant is available from launch, either, so the S6 provides a window into the top end of the A6 range.

While the entry level Audi A6 - now powered by a 1.8-litre TFSI engine - will most likely be the volume seller for the German brand, either of the two TDI models (the 3.0 TDI and 3.0 Biturbo) in the middle of the range are arguably the sweet spot. The 1.8 TFSI won’t let anyone down - we’ll get to that later - but if you do plenty of driving, the diesel engines are both exceptional.

The 3.0 TDI can be had for just under 100 grand, while the barnstorming twin-turbo diesel 3.0 TDI Biturbo can be yours for just under $125K. Whichever way you look at it, that’s a lot of Audi for the money, given the subtle technological advancements over the previous model.

The facelift is subtle but noticeable if you were to park the old and new models side-by-side and the grille detail especially makes a change to the front end. We love the array of LEDs at the front and rear of the A6 too, there’s nothing ‘add-on’ about them.

Our test run in the S6 allows us to access the 4.0-litre V8 engine, which generates a formidable 331kW between 5800-6400rpm and 550Nm from 1400-5700rpm.

While the power figure tends to get the headlines, the thumping torque, delivered just off idle makes a serious hole in the 0-100km/h time of 4.4 seconds. Despite performance that was a supercar standard not so long ago, an ADR fuel return of 9.5 litres per 100km is more than acceptable.

Of that list, I’d definitely have the Matrix headlights. Apart from being cool to look at, they actually work in the real world and are safer for the driver, as well as other road users. Park assist is also a must have, especially given the paltry $840 cost, and I’d opt for the sports exhaust too. The V8 engine makes the most glorious sound under hard acceleration that you’d be kicking yourself if you heard another S6 with the sports exhaust and you hadn’t ticked that option box - especially if it was your neighbour.

On Victoria’s winding, Yarra Valley roads, the S6 belies its sporting pretensions with comfortable ride quality and superior bump absorption. Even riding on 20-inch wheels, rutted roads can’t disturb the sense of calm in the cabin. It’s not as spongy as a base model Camry, for example, but it’s never uncomfortable either. Keep in mind that the majority of A6/S6 models will be plying their trade around town, so the car’s ability to fit in so effortlessly once you leave the city behind is impressive.

The handling is astounding for such a heavyweight sedan. The quattro drivetrain works its usual magic and results in an incredible, surefooted sense of grip and composure no matter how hard you push. Mid corner bumps don’t unsettle the grip either, the S6 never feels uncertain beneath you.

The steering has a beautiful meaty feel to it at speed, and the more enthusiastic drivers will fiddle with the drive settings to find the adjustments that best suit them. Even in Comfort mode, the S6 is a corner carver, and we noticed a distinct lack of understeer even when pushing a little harder into tighter corners, such is the alacrity of the quattro drivetrain.

Audi reckons the A6 range appeals to family buyers looking to step up in luxury or those who have the means to lust after a performance sedan. That’s certainly the case with the S6 variant, and even the Biturbo diesel variant too, which delivers performance beyond what you expect and certainly beyond the ADR fuel reading (6.1L/100km).

Perhaps the A6’s strongest trump card is the fact that there’s no diluting of the feeling of luxury or the drive experience behind the wheel of the 1.8 TFSI S tronic variant which weighs in just under 80 grand. Across the range, the A6 delivers strongly on what has now become signature Audi luxury - especially inside the cabin.

The entry level model is obviously not as powerful or urgent as the range-topper but it doesn't need to be. The 1.8 TFSI proves that you don’t need a monster engine to get up to legal speeds effortlessly, and the fuel consumption proves that you don’t need deep pockets to stay there either. The more sedate soundtrack means you can enjoy the cosseted sense of luxury from behind the wheel a bit more and get about your cruising duties in comfort.

The 1.8-litre engine does illustrate some minor turbo lag at times you don’t expect it. Its not a constant issue, but it can crop up during give and take driving in traffic.

Where the S6 is all sporting intent and fire and brimstone, the 1.8 TFSI variant is more about soothing the soul. Buyers will love its airy sense of space and practicality and it loses none of the external style, either. The A6 is, throughout the range, a stylish large sedan.

While our launch drive was all too short - that tends to happen when you’re launching multiple variants of more than one model - we’re looking forward to sampling the A6 range for our usual week-long test in the CarAdvice garage.

From launch, either of the two diesel-powered variants really do look to be the smart money choice in the range. That said, a week behind the wheel of the S6 might leave us wanting more.

Whichever way you look at it, the A6 range encompasses all that is great about the large sedan. Australian buyers might not love them as much as we once did, but there’s still a lot to like about the segment - particularly at the upper end.